The invention relates to an information transmission system, comprising at least one base station and at least one satellite station, which stations exchange their information by way of a plurality of time multiplexed signals which are transported in time slots over a plurality of carriers.
The invention also relates to a satellite station and a base station suitable for use in such a system.
A system of this kind is widely used notably in the field of private radio communications.
In this field a problem is encountered in that resources are scarce. In this context, "resource" refers to a number of frequency channels having more or less limited passbands. It is to be noted that despite these limited resources, the quality of the traffic must be as high as possible. A current source of traffic degrading is selective fading. A first known step for counteracting fading is the use of error correction codes; a second known step is the use of different frequency channels for the transmission of consecutive information. This step is described in detail in the article: "Performance of Trellis Coded Modulation Using Multi-Frequency Channels in Land Mobile Communications" by Yuklyoshi Kamio, Proc. of IEEE VEH. TECH., May 1990.
The present invention proposes a system of this kind in which notably the second step is executed, without suffering from the requirements often imposed by the authorities in view of the scarcity of resources.